All sorts of things happen in my mouth during panic attacks lol. Funny taste, bad breath and also very dry mouth. I think it is just normal cause your body is just reacting :) Also, some meds give metallic taste in mouth, especially when mouth is dry and panic often makes mouth dry. Anyway, if this bothers you too much call your doctor or local health line and they will clear it up for you :) Hope this helps :)
-Diva
